1. Field of the Invention
The present invention relates in general to the balancing of rotatable mechanical components and in particular to a balance weight construction and a method for securing one or more of such balance weights to a rotatable component of a vehicular drive train.
It is generally conceded that drive shafts are among the most troublesome components in modern vehicles, primarily because of their tendency to produce and transmit noise or vibration while transferring the power of the engine to the rear axle. This problem is becoming increasingly more serious because automobile manufacturers and consumers are demanding quieter and smoother cars with each succeeding model. The problem is further increased by the greater use of unitary automobile bodies, which bodies tend to accentuate noise and vibration.
Within recent years, there has been a noticeable increase in the problems of drive shaft balance and straightness on repaired or rebuilt shafts. These problems range from economy models to the more expensive cars, and in both single and compound drive shafts. Furthermore, as the gauge of the metal utilized in automobile bodies and frames is decreased and the weight of the engine, transmission, and differential becomes less, the problems associated with drive shaft imbalance become more critical.
2. Description of the Prior Art
Chapter Eight of the "Welding ALCOA Aluminum" booklet, published by the Aluminum Company of America of Pittsburgh, Pa. (undated), discloses the method of welding dissimilar materials utilizing the MIG-spot welding process. The details of the process are set forth on pages 93 through 95 therein. In particular, it is disclosed that an opening in one of the parts to be welded can provide a path for the molten filler metal wire.
Section 5 of "The Universal Joint Specialist" catalog, copyrighted in 1962 by Dana Corporation, generally discusses propeller shaft installation and replacement tips relating to propeller shaft balance. In particular, it is disclosed at page 72 therein that the correction of drive shaft imbalance can be accomplished with balancing weights or slugs which are added to the "light" side of the drive shaft. Although spot welding is desirable because it is a "cold" weld, arc or electric welding can be utilized successfully by tacking the weight or slug in two places to the shaft.
Chapter Eight of the "Universal Joint and Drive Shaft Design Manual", published in SAE Bulletin AE-7 in 1979, generally discusses the problems associated with the balancing of rotating bodies. In particular, it is disclosed at page 218 therein that the imbalance correction of vehicle drive shafts can be accomplished by projection welding suitably sized steel weights to the shaft at the proper angular locations in the correction planes.